Production of a protective layer on iron



Patented Oct. 26, 1937 UNITED STATES PRODUCTION OF A PROTECTIVE IRONLAYER N Walter Enders, Solingen-Ohligs, Germany No Drawing. ApplicationOctober 26, 1936, Serial No. 107,732. In Germany November 5, 1935Claims.

A great variety of processes are known for the production of aprotective layer on iron (steel), also by way of cementation, that is byheating the iron surrounded by a powder (cementation powder) in a closedcontainer. In this cementation powder aluminium powder usually plays thechief part.

According to the present invention a partibularly heat-resistingprotective layer is produced con is alloyed into the iron in a quantitywhich substantially affects the heat resistance. 0 A protective layer oniron (steel), produced in accordance with the invention, has proved tobe particularly resistant to high temperatures (not liable to formscale), but is also capable of with standing corrosion and wear.

For the rest the processwith aluminium and silicon is carried out in theknown manner. The powder consisting of aluminium and silicon is placedwith the article to be cemented in a closed container and brought to ahigh temperature, in the case under discussion to about 1000.

The process has been tried out with aluminium and silicon, .but besidesthe silicon another metalloid or metal may be'added, for instancechromium, manganese, titanium or the like. An ad' v dition of metaloxides or metal salts or any other non-metallic addition is howeverunnecessary and may even have a disturbing effect, as for instance 5 theaddition of binders.

What I claim is: Y

1. A process for the production of a protective layer on iron or steel,consisting in surrounding the iron with a powdered material consistingof 10 aluminium and silicon in a closed vessel and applying heatthereto, whereby the silicon as well as the aluminium become alloyedwith the iron ,to increase the heat resistance thereof.

2. A process for the production of a protective layer on iron or steel,consisting in surrounding the iron with a mixture of powdered aluminiumand powdered silicon in a closed vessel, and applying heatthereto,'whereby the silicon as well as the aluminium become alloyedwith the iron to increase the heat resistance thereof.

3. A process as claimed in claim 2 wherein the silicon content of themixture is 30 to 40%.

4. A process for the production of a protective layer on iron or steelconsisting insurrounding the iron with an aluminium silicon alloy inpowdered form in a closed vessel and applying heat thereto,'whereby thesilicon as'.well as the aluminium-become alloyed with the iron toincrease the heat resistance thereof.

5. A process as claimed in claim 4 wherein the silicon content of thealloy is to 40%.

WALTER ENDERS

